Sakai Y, Yurimoto H, Matsuo H, Kato N
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan.
Yeast. 1998 Sep 30;14(13):1175-87. doi: 10.1002/(SICI)1097-0061(19980930)14:13<1175::AID-YEA319>3.0.CO;2-7.
A methylotrophic yeast, Candida boidinii, was grown on various combinations of peroxisome-inducing carbon source(s) (PIC(s)), i.e. methanol, oleate and D-alanine, and the regulation of peroxisomal proteins (both matrix and membrane ones) and organelle proliferation were studied. This regulation was followed (1) at the protein or enzyme level by means of the peroxisomal enzyme activity and Western analysis; (2) at the mRNA level by Northern analysis; and (3) at the organelle level by direct observation of peroxisomes under a fluorescent microscope. Peroxisomal proliferation was followed in vivo by using a C. boidinii strain producing a green fluorescent protein having peroxisomal targeting signal 1. When multiple PICs were used for cell growth, C. boidinii induced specific peroxisomal proteins characteristic of all PIC(s) present in the medium, responding to all PIC(s) simultaneously. Thus, these PICs were considered to induce peroxisomal proliferation independently and not to repress peroxisomes induced by other PICs. Next, the sensitivity of the peroxisomal induction to glucose repression was studied. While the peroxisomal induction by methanol or oleate was completely repressed by glucose, the D-alanine-induced activities of D-amino acid oxidase and catalase, Pmp47, and the organelle proliferation were not. These results indicate that peroxisomal proliferation in yeasts is not necessarily sensitive to glucose repression. Lastly, this regulation was shown to occur at the mRNA level.
一种甲基营养型酵母——博伊丁假丝酵母（Candida boidinii），在过氧化物酶体诱导性碳源（PIC）的各种组合，即甲醇、油酸和D-丙氨酸上生长，并研究了过氧化物酶体蛋白（基质蛋白和膜蛋白）的调控以及细胞器增殖。这种调控通过以下方式进行跟踪：（1）在蛋白质或酶水平上，借助过氧化物酶体酶活性和蛋白质免疫印迹分析；（2）在mRNA水平上，通过Northern印迹分析；（3）在细胞器水平上，通过在荧光显微镜下直接观察过氧化物酶体。通过使用产生具有过氧化物酶体靶向信号1的绿色荧光蛋白的博伊丁假丝酵母菌株，在体内跟踪过氧化物酶体增殖。当使用多种PIC进行细胞生长时，博伊丁假丝酵母诱导出培养基中所有存在的PIC所特有的特定过氧化物酶体蛋白，同时对所有PIC做出反应。因此，这些PIC被认为是独立诱导过氧化物酶体增殖，而不是抑制其他PIC诱导的过氧化物酶体。接下来，研究了过氧化物酶体诱导对葡萄糖阻遏的敏感性。虽然甲醇或油酸诱导的过氧化物酶体被葡萄糖完全阻遏，但D-丙氨酸诱导的D-氨基酸氧化酶和过氧化氢酶活性、Pmp47以及细胞器增殖并未被阻遏。这些结果表明，酵母中的过氧化物酶体增殖不一定对葡萄糖阻遏敏感。最后，这种调控在mRNA水平上得以体现。
